25 October 2004
BACKGROUND ON THE USE OF LID. The use of LID was pioneered in the
1990s by the Prince George's County, Maryland Department of Environmental
Resources (PGDER). Prince George's County has a population of over 800,000, and
land uses within the County are very diverse, ranging from sparsely populated natural
and agricultural areas to densely populated urban centers. The LID effort in Prince
George's County began with the development and use of bioretention cells. A
bioretention cell is created by replacing existing soil with a highly porous soil mixture,
grading the area to form a shallow depression, and replanting the area with specially
selected vegetation. The vegetation must be able to tolerate temporarily saturated soil
conditions as well as the pollutants contained in the local runoff. When it rains,
bioretention areas collect the runoff and then filter out the pollutants as the water
passes down through the soil.
The County's initial experience with bioretention led to a full-scale effort to
incorporate LID into the County's resource protection program. In 1998, the County
produced the first municipal LID manual. This was later expanded into a nationally
distributed LID manual published in 2000.1 A feasibility study was prepared by the Low
Impact Development Center in 2002 that provided guidance on how LID could be used
to retrofit urban areas.2 Numerous municipalities, including Portland, Oregon,3 are
incorporating LID techniques into their urban resource protection programs. Although
LID concepts and techniques are new to many planners in the United States, many of
these techniques have been successfully used in Europe and Asia for many years.4
Several successful pilot projects have been constructed by the Navy and
other Department of Defense (DoD) agencies during the last several years. The
effectiveness of these projects in managing runoff, reducing construction and
maintenance costs, and creating ancillary benefits such as community involvement has
created significant interest in LID. The challenge is to adapt these approaches and
techniques to the unique requirements of DoD facilities on a wider scale.
INTRODUCTION TO UFC. This UFC provides guidelines for integrating LID
planning and design into a facility's regulatory and resource protection programs. It will
be useful to engineers, planners, maintenance personnel, regulatory compliance staff,
and community outreach staff who want a basic understanding of the technical and
administrative concepts associated with the design, construction, and maintenance of
LID features. The UFC answers the following questions:
What is LID and what value does it have for DoD facilities?
What are the basic planning, design, construction, and maintenance
How can this approach be incorporated into facility operations?
LID Center, 2002.